Fiber properties, changes related

However, this chapter is more focused on summarizing how different fillers and fibers affect PO properties. The next chapter will take on the burden of trying to relate these property-changing effects to artual end-use simations, to assist in the decision-making process for filled and reinforced POs (thus, all filler/fiber case studies are placed together in Chapter 8 rather than in this chapter). This chapter will limit itself to these questions ... 

The fact that both the hemicelluloses showed a weak transition at lower relative humidities is of great interest for the ductility of the fiber material. In general, materials with a secondary transition exhibit an increasing ductility when passing such a transition. Further studies of die structural causes for this transition within hemicelluloses are, however, necessary, in order to be able to relate this transition to product property changes. 

Stress—Strain Curve. Other than the necessity for adequate tensile strength to allow processibiUty and adequate finished fabric strength, the performance characteristics of many textile items are governed by properties of fibers measured at relatively low strains (up to 5% extension) and by the change ia these properties as a function of varyiag environmental conditions (48). Thus, the whole stress—strain behavior of fibers from 2ero to ultimate extension should be studied, and various parameters should be selected to identify characteristics that can be related to performance. 

Changes in electrical resistivity (V3) and mechanical properties (V3, V4) of graphite fibers upon nitration have been studied. Increases in elastic modulus, and decreases in tensile strengths, have been related to removal of boundary dislocations by the intercalation process proposed elsewhere iN4). 

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